The card uses warm colors too so this should do the trick.
All stamps and materials by Stampin' Up!
Stamps: Soft Summer and Oval All
Cardstock: Not Quite Navy, Old Olive, Confetti White cardstocks, and Bella Rose Designer Series Paper
Ink: Stazon Jet Black, Old Olive, Not Quite Navy
and Old Olive Marker
Accessories: AquaPainter, Eyelet Border Punch, Scallop Oval Punch, Large Oval Punch, White Gel Pen, Vanilla Taffeta Ribbon, and Dimensionals.
After stamping this card, it looked so dark it was depressing. Actually I had used an Old Olive ribbon first and took that off and used the Vanilla instead. It still needed brightening up, and that's where the White Gel Pen comes in to play. Can you see from the first picture the little design on the bottom edge of the card? It's just 4 dots with the Old Olive marker and then a white dot in the middle. It really seemed to brighten things up and was so easy to add. Dots were also added to the oval sentiment piece.
So if you ever need just an added spark of color, try adding some dots. You can use the White Gel Pen, any of the markers, a dot of glitter, or even a dot facsimile - brads, eyelets or piercing. With so many choices, I'm sure you'll find just the right accent for your creation.